Next-generation stent in operating theatres

OUR SPECIAL CORRESPONDENT

City cardiologists have started implanting in blocked arteries stents that will dissolve in the bloodstream in about a year.

The new type of stent, called the Bioresorbable Vascular Scaffold (BVS), could reduce complications sometimes caused by metallic stents, said doctors. In Calcutta, cardiologists had been using drug-eluting stents to treat coronary artery disease.

The stents that dissolve are made of polylactide, which provides support to the artery until it can stay open on its own. “The biggest advantage of the new generation of stent is that it dissolves completely and doesn’t cause the complications a metallic stent might cause,” said Rabin Chakraborty, interventional cardiologist and regional director and head of the heart institute at Apollo Gleneagles Hospital, Calcutta. He has implanted the new stent in three patients since last week.

The BVS, developed by US-based healthcare major Abbott, has been implanted in more than 3,000 patients and 30 countries worldwide in clinical trials, said a company official.

According to Chakraborty, the chance of restenosis (condition in which the artery is clogged some time after an angioplasty) was lower using the BVS than metallic stents. “For a drug-eluting stent, the chance of restenosis is less than seven per cent. But in a stent that dissolves, it’s less than two per cent,” he said.

If a metallic stent is implanted, the vessel would not function normally like before, as it would become non-reactive to drugs, said doctors. “Preliminary evidence suggests natural vessel function is possible and may improve long term outcomes. The new-generation stent allows the vessel to remain reactive to drugs,” said Anil Mishra, medical director, BM Birla Heart Research Centre.

Mishra implanted four BVSs in two patients recently. He said since the stent dissolves completely, multiple angioplasties would be possible.

However, doctors said the cost of the new type of stent was a deterrent — BVS costs around Rs 2.9 lakh, more than double the Rs 1.2 lakh average price of a drug-eluting stent.